Strainer

ABSTRACT

A fluid strainer and method of making same comprises an integral one-piece body having a mounting end, a strainer end and a cap member, both the strainer end and the cap member having a cross sectional dimension smaller than that of the strainer element. The strainer element is slid over the cap member and strainer end and is brought into abutting relationship with a shoulder which separates the mounting and strainer ends and the cross sectional dimension of the cap member is radially expanded in cross sectional dimension so as to engage the strainer element and firmly position and retain same on the strainer body.

4 ll Unliea States atent 1151 3,667,616 Wayne [4 1 June 6, 1972 STRAINER3,458,050 7/1969 Cooper ..210/448 1 t A] W D [72] nven or ex ayne esMomes Iowa Primary ExaminerSamih N. Zaharna [73] Assignee: DelavanManufacturing Company Assistant Examiner-R. W. Burks [22] Filed: OCL 29,1970 Attorney-Molinare, Allegretti, Newitt & Witcoff 21 Appl. No: 85,17057 ABSTRACT A fluid strainer and method of making same comprises an in-U-S. tegra] one-piece having a mounting end a trainer end [51] Int. Cl..B01d 35/28 and a Cap member, both the Strainer end and the cap member[58] Flew of Search 437, 448v having a cross sectional dimension smallerthan that of the 210/478 499 strainer element. The strainer element isslid over the cap member and strainer end and is brought into abuttingrelation- [56] References Cned ship with a shoulder which separates themounting and UNITED STATES PATENTS strainer ends and the cross sectionaldimension of the cap member 15 radially expanded in cross sectionaldimension so 284,428 9/1883 James ..210/497 X as to engage the strainerelement and fi l posiion and 292,912 2/1884 Heath 210/497 X retain Sameon the strainer body 1,137,480 4/1915 Gwynn.. ..210/497 X 2,198,8194/1940 Holm v.210/448 X 6 Claims, 3 Drawing Figures ea 1 T w s 4a IBACKGROUND AND SUMMARY OF THE INVENTION This invention relates to fluidstrainers and, more particularly, to an improved fluid strainer andmethod of making same.

In the past fluid strainers have generally been assembled by firstpositioning the strainer on the strainer body and then screwing orotherwise attaching an enlarged separately formed cap member on thestrainer body over the end of the strainer element to hold the elementin place. This construction is not only somewhat expensive, since thestrainer body and the cap member must be manufactured separately, butalso, since the strainer body and cap member are separate pieces, thelikelihood exists that the cap member will vibrate loose during use andeither become separated from the strainer or allow fluid to by-pass thestrainer without being strained.

In the present invention, the expense of such strainers is not onlyreduced, but also the possibility of separation or loosening of the capmember during use is avoided. In the present invention the cap memberand strainer body are formed in integral one-piece relationship and thecap member is subsequently compressively expanded in order to firmlyengage and retain the strainer element on the strainer body.

One aspect of the invention comprises a method of making a strainer ofthe type having a strainer element, a body having a first enlargedmounting end and a second strainer element carrying end which isseparated from the first end by a shoulder which is adapted to receivethe strainer element, and a longitudinal fluid passage extending throughthe first end and at least a part of the second end and communicatingwith the exterior of the second end. A cap member, having a crosssectional dimension which is smaller than the internal dimension of thestrainer element, is formed on the end of the second body end oppositethe shoulder in integral one-piece relationship with the body and inclosing relationship to the passage. The strainer element is then slidover the cap member and the second end against the shoulder and thecross sectional dimension of the cap member is enlarged by deforming thecap member to a larger dimension, such that it engages the strainerelement to firmly retain the strainer element on the second body end.

Another principal aspect of the invention comprises a strainer whichincludes a body having a first mounting portion, a second strainerelement carrying portion and a compressively expanded cap portion formedin integral one-piece relationship with the second portion. A shoulderis defined between the first and second portions and a strainer elementsurrounds the second portion and is retained thereon by the expanded capportion. A fluid passage extends through the body and is closed at oneend by the expanded cap portion and the passage communicates through thesecond portion of the body with the strainer element.

These and other objects, features and advantages of the presentinvention will be more clearly understood through a consideration of thefollowing detailed description.

BRIEF DESCRIPTION OF THE DRAWING In the course of this description,reference will frequently be made to the attached drawing in which:

FIG. I is a cross sectioned side elevation view through a preferredembodiment of strainer constructed in accordance with the principles ofthe invention and showing the strainer mounted for use in a spray nozzlebody;

FIG. 2 is an elevation view of the strainer shown in FIG. 1 in which thestrainer element is shown being installed on the strainer body; and

FIG. 3 is an elevation view of the strainer showing the cap member beingcompressively expanded to complete the assembly of the strainer.

DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of nozzlewhich is constructed in accordance with the principles of the inventionis shown in the drawings. The strainer may be, for example, of the typewhich is to be mounted directly in a spray nozzle body for insuring thatparticulate contaminates and other foreign matter which may be presentin the fluid stream which is to be sprayed are removed prior to thefluid stream arriving at the spray orifice and other close tolerancepassages in the nozzle device. Such typical spray nozzles may include anozzle body 10 having an elongate passage 12 therein which is open atboth ends for receiving an orifice disc 14, a fluid distributor 16, adistributor retainer 18, for maintaining the distributor and orificeplate firmly positioned in the body when the strainer mounting nipple 20is threaded against the distributor retainer by way of internal threads22 in the body andas shown in FIG. 1. The body 10 is also externallythreaded at 24 such that it may be mounted at the end of a suitablefluid delivery conduit 26. The retainer 18 is preferably cruciform incross section so as to define a plurality of radially extending arms 28,the fluid flow through the assembly being shown by the arrows in FIG. 1.The spray nozzle construction will not be further described in detailsince it does not form an essential part of the invention and is onlyillustrated to show how the preferred embodiment of strainer of theinvention may be employed in practice.

The preferred embodiment of strainer of the invention includes astrainer body, generally 30, which may be cast, machined or otherwisesuitably formed. The body 30 includes a first end or portion 32 havingthreads 34 defined thereon for cooperating with the internal threads 22to adapt the strainer to be mounted to a suitable structure, such as thenozzle body 10 shown in FIG. 1. The end portion 32 of the strainer body30 may also include a suitable tool receiving surface 36, such as anhexagonal or octagonal raised part, which is adapted to receive a wrenchor the like for mounting of the strainer.

The strainer body 30 also includes a second strainer element carryingportion or end 38 having a minimum cross sectional dimension which issmaller than the internal cross sectional dimension of a strainerelement 40 which is concentrically received thereon. One or more ribbedlands 42 may be provided on the external surface of body portion 38. Thecrests 44 of the lands preferably are positioned adjacent or 45 justtouch the interior of element 40 such that the strainer element issupported against collapse by the lands in a wellknown manner during thestraining operation. A plurality of apertures 46 are formed in thesecond body portion 38 to each side of the lands 42 and these aperturescommunicate the strainer element 40 with a longitudinally extendinginternal passage 48 in the strainer body so that filtered fluid whichhas passed through the strainer element will flow through the strainerbody 30 to the nozzle body 10 as shown by the arrows in FIG. 1.

The strainer element 40 may be formed of any one of several screenmaterials of suitable mesh size and composition depending upon thefluids which are to be filtered and the degree of filtration which isdesired. This screen material is formed into a sleeve which ispreferably rigid and which is shaped geometrically substantiallyidentical to the surface defined by the crests 44 of the land ribs 42and is received over the second portion so as to butt against a shoulder50 which separates the first and second body portions 32 and 38 fromeach other as shown in FIGS. 1 and 3.

Thus far, the strainer assembly which has been described issubstantially of the conventional type. In this conventional type ofstrainer, the strainer element 40 is usually retained in position on thesecond body end 38 by way of a separate cap member which is screwed orotherwise fixed to the right end of the body, as viewed in the drawings.As a result, the cost of such strainer device employing a separate capmember is increased and the possibility exists that the cap member andstrainer might become loose or separate from the remainder of thestrainer body during use. The latter disadvantage becomes particularlycritical where the strainer device is to be installed directly into anozzle body as shown in FIG. 1, since such nozzle bodies frequently aresubjected to substantial vibration in use. The strainer constructed inaccordance with the principles of the present invention not only effectsa reduction in the cost of manufacture over these prior strainerdevices, but also insures against loosening or separation of the capmember and strainer element during use.

In the present invention, the cap member 52 is formed, by way ofcasting, milling or the like, in integral one-piece relationship at theend of the strainer body portion 38. This cap member 52 is initiallyformed such that it has a cross sectional dimension smaller than theinternal dimension of the strainer element 40.

In order to assemble the strainer of the invention, the strainer element40 is first slid over the smaller dimensioned cap member 52 and onto thebody portion 38 as shown in FIG. 2, until it abuts against the shoulder50. As shown in FIG. 3, a mandrel 54, having substantially the samediameter as passage 48 is then inserted into the passage into contactagainst the internal side 56 of the cap member and a push rod 58 ispositioned to exert a force against the exterior surface 60 of the capmember to radially expand and deform the cap member so as to enlarge itscross sectional dimension to a dimension where it will engage thestrainer element 40 and retain the element between the cap member 52 andthe shoulder 50. The cap member 52 is preferably grooved at 62 about itsperimeter to insure that it will firmly engage the end internal surfaceof the strainer element 40 during compression and will retain same onthe strainer body.

Although in the embodiment shown and described, the cap member 52 isradially expanded such that it contacts the internal surface of thestrainer element 40, it will be appreciated that the length of thestrainer element may be such that the strainer element terminates justshort of the cap member prior to expansion of the latter. In thisconstruction, the cap member 52 will be expanded to a radial dimensionsomewhat larger than that of the strainer element 40 such that the capmember extends over and engages the end of the element to retain theelement on body portion 38, rather than engaging the internal surface.

it will be understood that the embodiment of the present invention whichhas been described is merely illustrative of an application of theprinciples of the invention. Numerous modifications may be made by thoseskilled in the art without departing from the true spirit and scope ofthe invention.

What is claimed is:

1. In a method of making a strainer for straining matter from a fluidstream and which includes, a strainer element, a body having a firstenlarged mounting end and a second smaller strainer element carrying endwhich is separated from said first body end by a shoulder which isadapted to receive said strainer element, and a longitudinal fluidpassage extending through said first body end and at least a part ofsaid second body end and communicating with the exterior surface of saidsecond body end, said method comprising the steps of:

forming a cap member on the end of said second body end opposite saidshoulder, said cap member being formed in integral one-piecerelationship with said body in closing relationship to said passage, andhaving a cross sectional dimension smaller than the internal dimensionof said strainer element, sliding said strainer element over saidsmaller cap member and said second body end into abutting relationshipwith said shoulder, and

enlarging the cross sectional dimension of said cap member bycompressively defomiing said cap member to a larger dimension such thatit engages said strainer element to firmly retain said element on saidsecond body end.

2. In the method of claim 1 wherein said step of enlarging said capmember includes compressing said cap member between first pressing meanswhich bears against the exterior surface of said cap member and secondpressing means which is inserted into said passa e.

3. In the method of c arm 1 wherein sald cap member engages the internalsurface of said strainer element when said cap member is compressivelydeformed.

4. A strainer for straining matter from a fluid stream comprising:

a body having a first mounting portion, a second strainer elementcarrying portion and a compressively expanded cap portion formed inintegral one-piece relationship with said second portion,

a shoulder defined between said first and second portions,

a strainer element surrounding said second portion and retained on saidshoulder by said expanded cap portion, and

a fluid passage extending through said body and closed at one end bysaid expanded cap portion, said passage communicating through saidsecond portion of said body with said strainer element.

5. The strainer of claim 4 wherein said first and second body portionsare also formed in integral one-piece relationship.

6. The strainer of claim 4 wherein the perimeter of said compressivelyexpanded cap portion engages the internal surface of said strainerelement.

1. In a method of making a strainer for straining matter from a fluidstream and which includes, a sTrainer element, a body having a firstenlarged mounting end and a second smaller strainer element carrying endwhich is separated from said first body end by a shoulder which isadapted to receive said strainer element, and a longitudinal fluidpassage extending through said first body end and at least a part ofsaid second body end and communicating with the exterior surface of saidsecond body end, said method comprising the steps of: forming a capmember on the end of said second body end opposite said shoulder, saidcap member being formed in integral onepiece relationship with said bodyin closing relationship to said passage, and having a cross sectionaldimension smaller than the internal dimension of said strainer element,sliding said strainer element over said smaller cap member and saidsecond body end into abutting relationship with said shoulder, andenlarging the cross sectional dimension of said cap member bycompressively deforming said cap member to a larger dimension such thatit engages said strainer element to firmly retain said element on saidsecond body end.
 2. In the method of claim 1 wherein said step ofenlarging said cap member includes compressing said cap member betweenfirst pressing means which bears against the exterior surface of saidcap member and second pressing means which is inserted into saidpassage.
 3. In the method of claim 1 wherein said cap member engages theinternal surface of said strainer element when said cap member iscompressively deformed.
 4. A strainer for straining matter from a fluidstream comprising: a body having a first mounting portion, a secondstrainer element carrying portion and a compressively expanded capportion formed in integral one-piece relationship with said secondportion, a shoulder defined between said first and second portions, astrainer element surrounding said second portion and retained on saidshoulder by said expanded cap portion, and a fluid passage extendingthrough said body and closed at one end by said expanded cap portion,said passage communicating through said second portion of said body withsaid strainer element.
 5. The strainer of claim 4 wherein said first andsecond body portions are also formed in integral one-piece relationship.6. The strainer of claim 4 wherein the perimeter of said compressivelyexpanded cap portion engages the internal surface of said strainerelement.